醋酸甲酯水解反应及产物分离工艺的改进研究

Improvement in the Process of Methyl Acetate Hydrolysis and Product Separation

针对现有的醋酸甲酯水解反应及产物分离工艺提出一种反应与精馏结合的改造方案。使用工厂提供的进口阳离子交换树脂作为催化剂在间歇反应器中对醋酸甲酯水解反应动力学进行了研究,结果表明,反应平衡常数随着温度的升高而增大,温度对反应速率的影响符合Arrhenius公式,反应速率与催化剂用量呈线性关系。在消除外扩散的影响下得到了醋酸甲酯非均相水解的反应速率方程为:dcMeAc-r=-1dt=k(cMeAccH2O-cMeOHcHAc/K)Mk=4.95954×105exp(-69682.7/RT)m6·kmol-1·min-1·kg-1K=exp(1.44707-1114.9/T)在此基础上通过模拟计算对改进工艺进行研究并确定,理论塔板数为20块的精馏塔和第二水解塔结合后进料位置为第10块塔板,侧线采出位置为第2～9块塔板,适宜回流比为1 2603。经比较表明,新工艺比原工艺节约能耗8 33%。

An improvement that combines hydrolysis with distillation is suggested to the process of methyl acetate hydrolysis and product separation.Kinetics of hydrolysis of methyl acetate catalyzed by an ionexchange resin is studied in a batch reactor.Experimental results show that equilibrium constant increases slightly with the increase of temperature,temperature has a significant effect on the reaction rate and the reaction rate changes linearly with the catalyst loading.Then,after elimination of outer diffusion,a complete kinetic equation for heterogeneous hydrolysis of methyl acetate is obtained:-r=-1MdcMeAcdt=k(cMeAccH2O-cMeOHcHAc/K)k=4.95954×105exp(-69682.7/RT)m6·kmol-1·min-1·kg-1K=exp(1.44707-1114.9/T)Research on the improved process is developed through a simulating calculation based on the kinetic equation.The distillation column having 20 theoretical trays is combined with a second reactor of hydrolysis. Its feed tray number,liquiddraw tray numbers and appropriate reflux ratio are determined as No.10,No.2～9 and 12603 respectively.As the result, the energy cost of the new process is 833% less than that of existing process.